All URL requests are "direct access" whether you type them in via the browser's navigation bar, they come in via AJAX, or an HTML GET/POST request. The server has no way of knowing the ultimate origin of a URL request.
So in that sense, you can't do anything.
However, if the idea is to preserve a workflow, you can verify the context at each stage to ensure that the preceding stages were satisfied and redirect back to the start page if they weren't.
Customer surveys are for companies who didn't pay proper attention to begin with.